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Kava Continues to Be a Mystery

Among “herbal” remedies for sleep, perhaps none has raised more questions over recent years than kava. Concerns about its safety have prompted extensive scientific study—and according to a recent large-scale review, we still don’t have answers to some basic questions about the risks associated with kava use.

In the roughly two decades it has been in popular use in the West, kava—a plant native to the South Pacific—has had a contentious and confusing history. Kava first became popular in the 1990s as an herbal remedy for sleep and anxiety. Within a few years, several cases of liver damage—and in some cases, liver failure—in the United States, Canada and European countries had been linked to kava consumption. Both the CDC and the FDA released warnings to consumers about the possible toxic side effects of kava. The cases of liver toxicity in Western countries remain relatively rare, but no explanation has ever been found for why kava can have toxic effects on people in Western cultures, when no similar toxic reaction exists among the South Pacific peoples who have used it regularly for centuries.

In many of the cultures of the South Pacific region, kava plays an important role in society. Because of its soothing, soporific effects, it is used medicinally to treat sleeplessness and anxiety. Kava is also part of social, cultural, and religious life in many countries throughout the South Pacific. Kava has been used for hundreds of years by Pacific Island people without the toxic effects that have been seen among people in Europe and the United States. (Though kava does not seem to have the same toxicity in people of the South Pacific region that it has shown in Westerners, kava use among Pacific Islanders is not free of difficulty. Excessive use of kava has led to social problems, according to some research.)

A team of researchers from the United States and Denmark conducted a comprehensive review of the scientific research related to kava, analyzing more than 85 studies, in an attempt to find a definitive explanation for kava toxicity in the West. They found no clear answer to their question. Though they weren’t able to identify a definitive cause of kava toxicity, researchers did confirm several theories that have been put forward, including:

Preparation. In traditional preparation of kava, the root of the plant is the only part used. One theory suggests that a toxic reaction may result from using other parts of the kava plant in addition to the root.

Species. There are several varieties of kava found in the South Pacific region. It’s possible that a particular variety used can cause a toxic reaction.

Genes. Researchers acknowledge that genetic differences among populations may play a role in kava toxicity.

With so much uncertainty surrounding kava and its possible side effects, it is simply not worth the risk. What’s more, sleeping aids in general—whether in the form of a prescription sleep medication or an over-the-counter remedy—are almost never the best first course of action. Medication for sleep may ultimately be the right choice for someone, but I always encourage my patients to start by making changes to their sleep habits, and their approach to sleep. (Any choice to use sleep medication or supplements should always be made in consultation with your doctor). Before relying on any supplement or chemical sleep aid, how about incorporating these sleep-smart strategies into your daily routine to improve your sleep hygiene:

Give your bio-clock a boost. Sunlight and exercise early in the day can help re-set your internal circadian rhythm, helping you feel more alert and awake during the daytime—and more inclined to sleep at night.

Watch what you drink. Be mindful not to overdo on caffeine during the morning, and don’t consume caffeinated beverages after 2 p.m. Alcohol can have disruptive effects on sleep—keep your overall consumption moderate, and don’t drink alcohol within 3 hours of your bedtime.

Stick to the routine. Studies indicate that adhering to routines throughout the day helps us sleep better at night. This includes regular times for meals, and exercise, as well as regular bed times and wake times. Make sure your routine includes a quiet hour before your actual bedtime—this is time to “power down,” quiet your mind, and engage in some simple, relaxing rituals before bed.

Create a bedroom that promotes good sleep. Your sleep environment is critical to the quality of your sleep. Research suggests that a clean bedroom leads to a better night’s sleep. Keeping electronics out of the bedroom is also important. Maintaining a cool, dark, clean room can help you fall asleep and stay asleep with fewer interruptions.

Science will continue to explore the mystery of kava, and we may someday understand its risks as well as its therapeutic potential.